KR19990070130A - Manufacturing method of adhesive tape for electronic parts - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive tape for electronic components having heat resistance, which is used for bonding between components around a lead frame such as a lead, a die pad, a heat sink, a semiconductor chip, and the like, in comparison with a conventional adhesive tape. It is designed to improve reliability.

The present invention is prepared by adding a predetermined amount of a bisphenol A epoxy and cresol novolac epoxy or a phenol novolac epoxy and an epoxy curing agent and fillers of inorganic or organic particles to an acrylic resin having a weight average molecular weight of 150,000 to 1,500,000 on one side or both sides of the heat resistant film. The adhesive tape is characterized by forming an adhesive layer by applying and drying the adhesive using the adhesive. The adhesive tape thus prepared is improved in general properties such as adhesive strength and heat resistance, and thus can be used as an electronic component such as a semiconductor chip. Very useful when

Description

Manufacturing method of adhesive tape for electronic parts

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat resistant adhesive tape for electronic components that can be used for bonding parts around a lead frame such as leads, die pads, heat sinks, semiconductor chips, and the like in semiconductor devices.

Conventionally, adhesive tapes used in resin-packaged semiconductor devices include adhesive tapes for fixing leadframes and TAB tapes. In the case of adhesive tapes for fixing leadframes, the leadframe itself is fixed by fixing the lead of the leadframe. It is used for the purpose of improving the yield and productivity of the entire semiconductor assembly process, and is generally bonded onto a lead frame in a lead frame maker, and the semiconductor maker uses it to package the semiconductor chip and then package it with a resin. The adhesive tape for fixing the leadframe must have sufficient heat resistance to withstand the general reliability at the semiconductor level and the workability during taping, as well as the adhesive strength after taping and the heating in the assembly process of the semiconductor device.

Conventional adhesive tapes used for such applications include, for example, synthetic rubber resins such as polyacrylonitrile, polyacrylates or acrylonitrile-butadiene copolymers on heat resistant support films such as polyimide films. Is used alone or modified with another resin or coated with an adhesive mixed with another resin.

In recent years, the structure of the package has become complicated due to polyfinization and heat dissipation in the semiconductor device, and the demand for electrical, physical and handling characteristics is also strict for organic materials such as adhesive tapes used therein. .

For example, in fixing a lead pin in a resin-sealed semiconductor device, when a conventional adhesive tape is used, heat resistance and electrical reliability may not be sufficient, and heat sinks and lead pins may be bonded together, or semiconductor chips and lead pins may be bonded. Is bonded to the insulating tape, there is a problem that the taping temperature, pressure, curing conditions, etc. are strict, which may damage metal materials such as lead frames, and are difficult to reduce cost.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide an adhesive tape for an electronic component that can be bonded and cured at a relatively low temperature and has sufficient heat resistance and reliability.

The present invention is an acrylic resin having a weight average molecular weight of 150,000 to 1,500,000 on one side or both sides of a heat resistant film, having a glass transition temperature in the range of -10 to 70 ° C, and a carboxyl group, an amine group, a glycidyl group, a sulfone group, an alcohol group as a functional group. 50 to 600 parts by weight of bisphenol A epoxy based on 100 parts by weight of an acrylic resin and cresol novolac epoxy or phenol novolac epoxy to 100 parts by weight of the acrylic resin, having at least one functional group among amino groups. To 200 parts by weight, an aromatic diamine-based or acid-anhydride-based curing agent having excellent electrical and heat resistance properties as an epoxy resin curing agent is added in an amount of 5 to 30 parts by weight based on 100 parts by weight of the epoxy resin, and an inorganic or organic component as a filler. It is produced by coating and drying the adhesive prepared by adding 1 to 10 parts by weight of particles to 100 parts by weight of acrylic resin. It relates to an adhesive tape for an electronic component.

Hereinafter, the present invention will be described in detail.

The acrylic resin used in the present invention has a weight average molecular weight of 150,000 to 1,500,000, and the monomer composition ratio is 10 to 60% by weight of acrylonitrile and 20 to 70% by weight of alkyl acrylate having an alkyl group having 2 to 12 carbon atoms. And a monomer having at least one functional group from a double bond and a carboxyl group, an alcohol group, an amine group, a sulfone group, and an amino group in the range of 0.1 to 20% by weight. This acrylic resin is synthesized by emulsion polymerization. After precipitation of resin using strong alkali, water is removed and dissolved in solvent.

At this time, if the weight average molecular weight is lower than 150,000, the thermal stability is poor and the heat resistance is lowered. If the weight average molecular weight is higher than 1,500,000, the solubility in solvent is worsened. The castle is degraded. Moreover, when acrylonitrile content rate becomes lower than 10 weight%, heat resistance and chemical resistance will fall, and when higher than 60 weight%, adhesive force will become bad. When the monomer having a functional group is lower than 0.1% by weight, the adhesive strength and heat resistance are lowered, and when the monomer having a functional group is higher than 20% by weight, the stability in solution is lowered, resulting in poor workability.

In the case of the epoxy resin used in the present invention, the bisphenol A epoxy is 50 to 600 parts by weight (more preferably 100 to 200 parts by weight) with respect to 100 parts by weight of the acrylic resin, and cresol novolac epoxy is 100 parts by weight of the component acrylic resin. An epoxy resin composed of 30 to 200 parts by weight (more preferably, 50 to 100 parts by weight) is used. In this case, when less than 50 parts by weight of bisphenol A epoxy is used, the adhesive strength is lowered, and when excessively used, heat resistance is lowered, and when cresol novolac epoxy is less than 30 parts by weight, heat resistance is worsened and excessively used. Adhesive strength is reduced.

In the present invention, the epoxy curing agent should be contained in an appropriate amount with respect to the epoxy content, and if insufficient or excessive, solvent resistance, heat resistance, electrical resistance, etc. are lowered. The curing agent may be an acid anhydride-based or aromatic diamine curing agent having excellent electrical properties, heat resistance, and chemical resistance, and a curing accelerator may be used to promote the curing reaction.

In the case of inorganic or organic particles, it is preferable to add 1 to 100 parts by weight with respect to 100 parts by weight of acrylic resin. If this is insufficient, the adhesiveness is excessive due to excessive adhesiveness. In this case, inorganic fillers that can be used include zinc oxide, silica, alumina, and zircon powder, and the like, and organic fillers include acrylic, nylon, and silicon.

The adhesive prepared with the above composition has a suitable viscosity in the range of 100 to 2000 cps (more preferably 300 to 1000 cps).

In the present invention, the above adhesive is applied on the heat-resistant film so as to have a thickness of 10 to 50 μm after drying, and dried at 80 to 120 ° C. for 1 to 20 minutes, and then a peelable film is attached at 80 to 120 ° C. for 5 to 30 minutes. Through the process of semi-hardening, the desired heat resistant adhesive tape is manufactured.

In this case, as the heat resistant film that can be used, for example, a heat resistant resin film such as polyimide, polyphenylene sulfide, polyether, polyparabenic acid, polyethylene terephthalate, or the like may be used, but a polyimide resin film is particularly preferable.

The thickness of the heat resistant film is preferably set in the range of 5 to 100 µm (more preferably 10 to 75 µm). When the thickness is too thin, the adhesive tape is soft and difficult to handle. Since punching property becomes difficult, the said range is preferable.

In the case of a peelable film, the thickness of 10-200 micrometers, Preferably it is 25-150 micrometers is used, The usable peelable film is a polypropylene film, a fluororesin film, a polyethylene film, a polyethylene terephthalate film, paper, and a case. According to this, those given to peelability with a silicone resin can be used.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1

30 parts by weight of acrylonitrile, 65 parts by weight of butyl acrylate and 5 parts by weight of methacrylic acid were mixed together with distilled water and an emulsifier to prepare a monomer mixture. As a polymerization initiator, KPS was dissolved in distilled water, the temperature was raised to 70 ° C., and the monomer mixture prepared beforehand was added dropwise for 3.5 hours while stirring. Then, the aging reaction was further performed at 70 ° C. for 4.5 hours. After the reaction was completed and the temperature was cooled to room temperature, 10% NaOH solution was added to precipitate the resin. The precipitated resin was filtered off and washed with water three to four times, followed by drying at 60 ° C. in a vacuum oven. The weight average molecular weight of the resulting acrylic resin was 1,200,000.

100 parts by weight of the acrylic resin obtained as described above was dissolved in methyl ethyl ketone to prepare a 15% by weight solution. Then, 150 parts by weight of bisphenol A epoxy (400 equivalents), 80 parts by weight of cresol novolac epoxy (200 equivalents), dia 25 parts by weight of minodiphenylsulfone and 6 parts by weight of zinc oxide were added, and the viscosity of the solution was adjusted to 800 to 1000 cps using methyl ethyl ketone and a toluene solvent.

Using this adhesive, a polyimide film having a thickness of 50 µm (trade name: manufactured by KAPTON, DUPONT) was applied so that the thickness after drying was 20 µm, dried (120 ° C. for 5 minutes), and then 38 µm in polyethylene tere. A phthalate film was laminated to prepare an adhesive tape.

Example 2

30 parts by weight of acrylonitrile, 65 parts by weight of butyl acrylate and 5 parts by weight of glycidyl acrylate were mixed together with distilled water and an emulsifier to prepare a monomer mixture. As a polymerization initiator, KPS was dissolved in distilled water, the temperature was raised to 70 ° C., and the monomer mixture prepared beforehand was added dropwise for 3.5 hours while stirring, and then aged at 4.5 ° C. for 4.5 hours. After the reaction was completed and the temperature was cooled to room temperature, 10% NaOH solution was added to precipitate the resin. The precipitated resin was filtered off and washed with water three to four times, followed by drying at 60 ° C. in a vacuum oven. The weight average molecular weight of the resulting acrylic resin was 1,200,000.

To 100 parts by weight of acrylic resin, 200 parts by weight of bisphenol A epoxy, 100 parts by weight of cresol novolac epoxy, 30 parts by weight of diaminodiphenylsulfone, and 10 parts by weight of zinc oxide were added to prepare a methyl ethyl ketone and a toluene solvent as in Example 1. The viscosity of the solution was adjusted to 800 to 1000 cps, and then the adhesive tape was prepared in the same manner as in Example 1 using this adhesive.

Comparative Example 1

35 parts by weight of acrylonitrile and 65 parts by weight of butyl acrylate were mixed together with distilled water and an emulsifier to prepare a monomer mixture. As a polymerization initiator, KPS was dissolved in distilled water, the temperature was raised to 70 ° C, and the prepared monomer mixture was added dropwise for 3.5 hours while stirring, and then aged at 4.5 ° C for 4.5 hours. After the reaction was completed and the temperature was cooled to room temperature, 10% NaOH solution was added to precipitate the resin. The precipitated resin was filtered off and washed with water three to four times, followed by drying at 60 ° C. in a vacuum oven. The weight average molecular weight of the resulting acrylic resin was 1,400,000.

100 parts by weight of the acrylic resin obtained as described above was dissolved in methyl ethyl ketone to prepare a 15% by weight solution. Then, 150 parts by weight of bisphenol A epoxy (400 equivalents), 80 parts by weight of cresol novolac epoxy (200 equivalents), dia 25 parts by weight of minodiphenylsulfone and 6 parts by weight of zinc oxide were added, and the viscosity of the solution was adjusted to 800 to 1000 cps using methyl ethyl ketone and a toluene solvent. An adhesive tape was prepared in the same manner as in Example 1 using this adhesive.

Comparative Example 2

7 parts by weight of acrylonitrile, 80 parts by weight of butyl acrylate, 5 parts by weight of glycidyl acrylate, and 8 parts by weight of hydroxyethyl methacrylate were mixed with distilled water and an emulsifier to prepare a monomer mixture. As a polymerization initiator, KPS was dissolved in distilled water, the temperature was raised to 70 ° C., and the monomer mixture prepared beforehand was added dropwise for 3.5 hours while stirring, and then aged at 4.5 ° C. for 4.5 hours. After the reaction was completed and the temperature was cooled to room temperature, 10% NaOH solution was added to precipitate the resin. The precipitated resin was filtered off and washed with water three to four times, followed by drying at 60 ° C. in a vacuum oven. The weight average molecular weight of the resulting acrylic resin was 1,400,000.

100 parts by weight of the acrylic resin obtained as described above was dissolved in methyl ethyl ketone to prepare a 15% by weight solution. Then, 150 parts by weight of bisphenol A epoxy (400 equivalents), 80 parts by weight of cresol novolac epoxy (200 equivalents), dia 25 parts by weight of minodiphenylsulfone and 6 parts by weight of zinc oxide were added, and the viscosity of the solution was adjusted to 800 to 1000 cps using methyl ethyl ketone and a toluene solvent. An adhesive tape was prepared in the same manner as in Example 1 using this adhesive.

Comparative Example 3

30 parts by weight of acrylonitrile, 65 parts by weight of butyl acrylate and 5 parts by weight of glycidyl acrylate were mixed together with distilled water and an emulsifier to prepare a monomer mixture. As a polymerization initiator, KPS was dissolved in distilled water, the temperature was raised to 70 ° C, and the prepared monomer mixture was added dropwise for 3.5 hours while stirring, and then aged at 4.5 ° C for 4.5 hours. After the reaction was completed and the temperature was cooled to room temperature, 10% NaOH solution was added to precipitate the resin. The precipitated resin was filtered off and washed with water three to four times, followed by drying at 60 ° C. in a vacuum oven. The weight average molecular weight of the resulting acrylic resin was 1,200,000. 100 parts by weight of bisphenol A epoxy, 20 parts by weight of cresol novolac epoxy, 10 parts by weight of diaminodiphenylsulfone, and 8 parts by weight of zinc oxide were added to 100 parts by weight of the acrylic resin, to obtain a methyl ethyl ketone and a toluene solvent. Was used to adjust the viscosity of the solution to 800 to 1000 cps. An adhesive tape was prepared in the same manner as in Example 1 using this adhesive.

The properties of the adhesive tapes prepared in Examples and Comparative Examples were evaluated by the following method, and the results are shown in Table 1.

Adhesion

The copper foil was placed on a hot plate maintained at 150 ° C., and the TAPE prepared in Examples and Comparative Examples was pressed at a pressure of 5 kg / cm 2 for 0.5 seconds, and then cured at 175 ° C. hot air oven for 1 hour, followed by tensile strength tester. T-PEEL strength

Pyrolysis temperature

Measuring with DuPONT V4.1C 2200 Model TGA

Moisture absorption

Soak in 23 ℃ water for 24 hours and measure weight change

TABLE 1

Evaluation item Adhesive force (g / cm) Pyrolysis Temperature (℃) Hygroscopicity (%) Example 1 860 370 1.8 Example 2 740 395 1.6 Example 3 920 395 1.7 Comparative Example 1 430 350 1.2 Comparative Example 2 420 320 1.9 Comparative Example 3 750 315 1.7

As can be seen from the above examples and comparative examples, the adhesive tape prepared according to the present invention has increased adhesive strength and exhibits excellent properties such as heat resistance and aging stability, and thus is applied to electronic parts such as semiconductor chips. Especially useful effects can be obtained.

Claims (2)

When adhesive is formed on one or both sides of the heat resistant film to form an adhesive layer, the adhesive tape is produced. The glass transition temperature is -10∼70 ℃ as the acrylic resin as the adhesive and the carboxyl group, amine group, glycidyl group, liquor as the functional group. 50 to 600 parts by weight of bisphenol A epoxy and 30 to 200 parts by weight of cresol novolac epoxy or phenol novolac epoxy are added to 100 parts by weight of a poly group having an at least one functional group among an phon group, an alcohol group and an amino group, A diamine-based or acid-anhydride-based curing agent is added in an amount of 5 to 30 parts by weight based on 100 parts by weight of epoxy resin, and an adhesive obtained by adding 1 to 10 parts by weight of inorganic or organic particles to 100 parts by weight of acrylic resin is used as a filler. Adhesive tape manufacturing method for an electronic component, characterized in that. The acrylic resin according to claim 1, wherein the acrylic resin has a monomer composition ratio of 10 to 60% by weight of acrylonitrile, 20 to 70% by weight of alkyl acrylate having an alkyl group having 2 to 12 carbon atoms, a double bond, a carboxyl group, an alcohol group, A method for producing an adhesive tape for an electronic component, characterized in that the content of a monomer having at least one functional group among amine groups, sulfone groups, and amino groups is 0.1 to 2.0% by weight.